CVE-2012-0884

La implementación de Cryptographic Message Syntax (CMS) y PKCS #7 de OpenSSL anteriores a 0.9.8u y 1.x anteriores a 1.0.0h no restringe apropiadamente un determinado uso de información posterior ("oracle behavior"), lo que facilita a atacantes dependientes del contexto desencriptar datos a través de un ataque de tipo "Million Message Attack (MMA) adaptive chosen ciphertext".

OpenSSL is a toolkit that implements the Secure Sockets Layer and Transport Layer Security protocols, as well as a full-strength, general purpose cryptography library. A NULL pointer dereference flaw was found in the way OpenSSL parsed Secure/Multipurpose Internet Mail Extensions messages. An attacker could use this flaw to crash an application that uses OpenSSL to decrypt or verify S/MIME messages. A flaw was found in the PKCS#7 and Cryptographic Message Syntax implementations in OpenSSL. An attacker could possibly use this flaw to perform a Bleichenbacher attack to decrypt an encrypted CMS, PKCS#7, or S/MIME message by sending a large number of chosen ciphertext messages to a service using OpenSSL and measuring error response times.